// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_CERT_CERT_VERIFY_PROC_H_
#define NET_CERT_CERT_VERIFY_PROC_H_

#include <string>
#include <vector>

#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "net/base/net_export.h"
#include "net/cert/x509_cert_types.h"

namespace net {

class CertVerifyResult;
class CRLSet;
class X509Certificate;
typedef std::vector<scoped_refptr<X509Certificate>> CertificateList;

// Class to perform certificate path building and verification for various
// certificate uses. All methods of this class must be thread-safe, as they
// may be called from various non-joinable worker threads.
class NET_EXPORT CertVerifyProc
    : public base::RefCountedThreadSafe<CertVerifyProc> {
public:
    // Creates and returns the default CertVerifyProc.
    static CertVerifyProc* CreateDefault();

    // Verifies the certificate against the given hostname as an SSL server
    // certificate. Returns OK if successful or an error code upon failure.
    //
    // The |*verify_result| structure, including the |verify_result->cert_status|
    // bitmask, is always filled out regardless of the return value. If the
    // certificate has multiple errors, the corresponding status flags are set in
    // |verify_result->cert_status|, and the error code for the most serious
    // error is returned.
    //
    // |ocsp_response|, if non-empty, is a stapled OCSP response to use.
    //
    // |flags| is bitwise OR'd of VerifyFlags:
    //
    // If VERIFY_REV_CHECKING_ENABLED is set in |flags|, online certificate
    // revocation checking is performed (i.e. OCSP and downloading CRLs). CRLSet
    // based revocation checking is always enabled, regardless of this flag, if
    // |crl_set| is given.
    //
    // If VERIFY_EV_CERT is set in |flags| too, EV certificate verification is
    // performed.
    //
    // |crl_set| points to an optional CRLSet structure which can be used to
    // avoid revocation checks over the network.
    //
    // |additional_trust_anchors| lists certificates that can be trusted when
    // building a certificate chain, in addition to the anchors known to the
    // implementation.
    int Verify(X509Certificate* cert,
        const std::string& hostname,
        const std::string& ocsp_response,
        int flags,
        CRLSet* crl_set,
        const CertificateList& additional_trust_anchors,
        CertVerifyResult* verify_result);

    // Returns true if the implementation supports passing additional trust
    // anchors to the Verify() call. The |additional_trust_anchors| parameter
    // passed to Verify() is ignored when this returns false.
    virtual bool SupportsAdditionalTrustAnchors() const = 0;

    // Returns true if the implementation supports passing a stapled OCSP response
    // to the Verify() call. The |ocsp_response| parameter passed to Verify() is
    // ignored when this returns false.
    virtual bool SupportsOCSPStapling() const = 0;

protected:
    CertVerifyProc();
    virtual ~CertVerifyProc();

private:
    friend class base::RefCountedThreadSafe<CertVerifyProc>;
    FRIEND_TEST_ALL_PREFIXES(CertVerifyProcTest, DigiNotarCerts);
    FRIEND_TEST_ALL_PREFIXES(CertVerifyProcTest, TestHasTooLongValidity);

    // Performs the actual verification using the desired underlying
    // cryptographic library. On entry, |verify_result->verified_cert|
    // is set to |cert|, the unverified chain. If no chain is built, the
    // value must be left untouched.
    virtual int VerifyInternal(X509Certificate* cert,
        const std::string& hostname,
        const std::string& ocsp_response,
        int flags,
        CRLSet* crl_set,
        const CertificateList& additional_trust_anchors,
        CertVerifyResult* verify_result)
        = 0;

    // Returns true if |cert| is explicitly blacklisted.
    static bool IsBlacklisted(X509Certificate* cert);

    // IsPublicKeyBlacklisted returns true iff one of |public_key_hashes| (which
    // are hashes of SubjectPublicKeyInfo structures) is explicitly blocked.
    static bool IsPublicKeyBlacklisted(const HashValueVector& public_key_hashes);

    // HasNameConstraintsViolation returns true iff one of |public_key_hashes|
    // (which are hashes of SubjectPublicKeyInfo structures) has name constraints
    // imposed on it and the names in |dns_names| are not permitted.
    static bool HasNameConstraintsViolation(
        const HashValueVector& public_key_hashes,
        const std::string& common_name,
        const std::vector<std::string>& dns_names,
        const std::vector<std::string>& ip_addrs);

    // The CA/Browser Forum's Baseline Requirements specify maximum validity
    // periods (https://cabforum.org/Baseline_Requirements_V1.pdf):
    //
    // For certificates issued after 1 July 2012: 60 months.
    // For certificates issued after 1 April 2015: 39 months.
    //
    // For certificates issued before the BRs took effect, there were no
    // guidelines, but clamp them at a maximum of 10 year validity, with the
    // requirement they expire within 7 years after the effective date of the BRs
    // (i.e. by 1 July 2019).
    static bool HasTooLongValidity(const X509Certificate& cert);

    DISALLOW_COPY_AND_ASSIGN(CertVerifyProc);
};

} // namespace net

#endif // NET_CERT_CERT_VERIFY_PROC_H_
